header {
    position: sticky;
    display: flex;
    align-items: center;
    height: 80px;
    padding-top: 15px;
    padding-bottom: 15px;
    max-width: 1024px;
    margin: 0 auto;
    overflow: hidden;
    top: 0;
    z-index: 999999;
}

header nav {
    display: flex;
    background-color: var(--dark);
    padding: 0 15px;
    border-radius: 999px;
}

#logo {
    display: flex;
    align-items: center;
    margin-right: 35px;
}

#logo img {
    width: 30px;
    height: 30px;
    margin: 0 8px;
}

.nav-item {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 50px;
    margin: 0 10px;
    font-size: 18px;
}

#menu {
    display: none;
}

.mobile-nav {
    display: none;
}

@media screen and (max-width: 640px) {
    header {
        padding-left: 2vmin;
        padding-right: 2vmin;
        background-color: rgba(0, 0, 0, .4);
        backdrop-filter: blur(24px);
    }

    header nav {
        display: none
    }

    .mobile-nav {
        position: fixed;
        left: 0;
        right: 0;
        height: 0;
        display: block;
        background-color: rgba(0, 0, 0, .4);
        backdrop-filter: blur(24px);
        overflow: hidden;
        transition: height 500ms;
    }

    .mobile-nav.open {
        height: 100vh;
    }

    .mobile-nav .nav-item {
        justify-content: left;
    }

    #menu {
        position: relative;
        display: flex;
        align-items: center;
        width: 7vmin;
        height: 7vmin;
    }

    #menu span {
        position: relative;
        width: 100%;
    }

    #menu span::before,  #menu span::after{
        content: '';
        position: absolute;
        width: 100%;
        height: 0.3vmin;
        border-radius: 999px;
        background-color: #fff;
        transition: transform 300ms;
    }

    #menu span::before {
        transform: translateY(1vmin) rotate(0deg);
    }

    #menu span::after {
        transform: translateY(-1vmin) rotate(0deg);
    }

    #menu.open span::before {
        transform: translateY(0) rotate(-45deg);
    }

    #menu.open span::after {
        transform: translateY(0) rotate(45deg);
    }
}